Excessive Oil Consumption/Exhaust Smoke; Engine Tends To Cut-Off At Full Throttle/At Idle; Engine Stops At Full Throttle/At Idle - Derbi GP1 50 cc Workshop Manual

EXCESSIVE OIL CONSUMPTION/EXHAUST SMOKE

CAUSES POSSIBLE
Excessive carbon deposits on cylinder ports
and in combustion chamber
ENGINE TENDS TO CUT-OFF AT FULL THROTTLE
E
NGINE STOPS AT FULL THROTTLE
CAUSES POSSIBLE
Maximum jet dirty - lean carburetion
Fuel cock failure
Water in the carburettor
Float valve faulty
Float valve defective
Fuel vent pipe colgged
ENGINE TENDS TO CUT-OFF AT IDLE
E
NGINE STOPS AT IDLE
CAUSES POSSIBLE
Idle nozzle dirty
The choke stays open
The reed valve does not close
Slow running incorrectly tuned up
Spark plug faulty
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WORK
Decoke
WORK
Wash with solvent and dry with compressed air.
Check that the fuel comes through the feed pipe when
the engine is started, with the throttle closed; if not,
replace the vacuum cock.
Empty the basin by the special drain.
Check float sliding and needle valve operation.
Check float and needle sliding.
Resorte the proper tank aeration.
WORK
Wash with solvent and dry with compressed air
Check: electrical connections, circuit continuity, me-
chanical sliding and power supply
Check / replace the reed pack
Tune up slow running and check C.O. level
Replace spark plug with an equivalent part having the
prescribed heat grade. Check electrodes gap